/**
 * v-dialogDrag 弹窗拖拽
 * Copyright (c) 2023 兮玥（190785909@qq.com）
 */
export default {
  bind(el, binding, vnode, oldVnode) {
      const value = binding.value
      if (value == false) return
      // 获取拖拽内容头部
      const dialogHeaderEl = el.querySelector('.el-dialog__header');
      const dragDom = el.querySelector('.el-dialog');
      dialogHeaderEl.style.cursor = 'move';
      // 获取原有属性 ie dom元素.currentStyle 火狐谷歌 window.getComputedStyle(dom元素, null);
      const sty = dragDom.currentStyle || window.getComputedStyle(dragDom, null);
      dragDom.style.position = 'absolute';
      dragDom.style.marginTop = 0;
      let width = dragDom.style.width;
      if (width.includes('%')) {
          width = +document.body.clientWidth * (+width.replace(/\%/g, '') / 100);
      } else {
          width = +width.replace(/\px/g, '');
      }
      // dragDom.style.left = `${(document.body.clientWidth - width) / 2}px`;
      dragDom.style.left = '50%';
      dragDom.style.top = '20%';
      dragDom.style.transform = 'translateX(-50%)';
      // 鼠标按下事件
      dialogHeaderEl.onmousedown = (e) => {
          // 鼠标按下，计算当前元素距离可视区的距离 (鼠标点击位置距离可视窗口的距离)
          const disX = e.clientX - dialogHeaderEl.offsetLeft;
          const disY = e.clientY - dialogHeaderEl.offsetTop;

          // 获取到的值带px 正则匹配替换
          let styL, styT;

          // 注意在ie中 第一次获取到的值为组件自带50% 移动之后赋值为px
          if (sty.left.includes('%')) {
              styL = +document.body.clientWidth * (+sty.left.replace(/\%/g, '') / 100);
              styT = +document.body.clientHeight * (+sty.top.replace(/\%/g, '') / 100);
          } else {
              styL = +sty.left.replace(/\px/g, '');
              styT = +sty.top.replace(/\px/g, '');
          };

          // 鼠标拖拽事件
          document.onmousemove = function (e) {
              // 通过事件委托，计算移动的距离 （开始拖拽至结束拖拽的距离）
              const l = e.clientX - disX;
              const t = e.clientY - disY;

              let finallyL = l + styL
              let finallyT = t + styT

              // 移动当前元素
              dragDom.style.left = `${finallyL}px`;
              dragDom.style.top = `${finallyT}px`;

          };

          document.onmouseup = function (e) {
              document.onmousemove = null;
              document.onmouseup = null;
          };
      }
  }
};